Method for fabricating an interference display unit

ABSTRACT

An interference display unit with a first electrode, a second electrode and posts located between the two electrodes is provided. The characteristic of the interference display unit is that the second electrode&#39;s stress is released through a thermal process. The position of the second electrode is shifted and the distance between the first electrode and the second electrode is therefore defined. A method for fabricating the structure described as follow. A first electrode and a sacrificial layer are sequentially formed on a substrate and at least two openings are formed in the first electrode and the sacrificial layer. A supporter is formed in the opening and the supporter may have at least one arm on the top portion of the supporter. A second electrode is formed on the sacrificial layer and the supporter and a thermal process is performed. Finally, The sacrificial layer is removed.

FIELD OF INVENTION

The present invention relates to a method for manufacturing an opticalinterference display. More particularly, the present invention relatesto a method for manufacturing an optical interference display with postsof arms.

BACKGROUND OF THE INVENTION

Planar displays are popular for portable displays and displays withspace limits because they are light and small in size. To date, planardisplays in addition to liquid crystal displays (LCD), organicelectro-luminescent displays (OLED), plasma display panels (PDP) and soon, as well as a mode of the optical interference display are ofinterest.

U.S. Pat. No. 5,835,255 discloses an array of display units of visiblelight that can be used in a planar display. Please refer to FIG. 1,which depicts a cross-sectional view of a display unit in the prior art.Every optical interference display unit 100 comprises two walls, 102 and104. Posts 106 support these two walls 102 and 104, and a cavity 108 issubsequently formed. The distance between these two walls 102 and 104,that is, the length of the cavity 108, is D. One of the walls 102 and104 is a hemi-transmissible/hemi-reflective layer with an absorptionrate that partially absorbs visible light, and the other is a lightreflective layer that is deformable when voltage is applied. When theincident light passes through the wall 102 or 104 and arrives in thecavity 108, in all visible light spectra, only the visible light withthe wavelength corresponding to the formula 1.1 can generate aconstructive interference and can be emitted, that is,2D=Nλ  (1.1)

-   -   where N is a natural number.

When the length D of cavity 108 is equal to half of the wavelength timesany natural number, a constructive interference is generated and a sharplight wave is emitted. In the meantime, if the observer follows thedirection of the incident light, a reflected light with wavelength λ₁can be observed. Therefore, the display unit 100 is “open”.

The first wall 102 is a hemi-transmissible/hemi-reflective electrodethat comprises a substrate, an absorption layer, and a dielectric layer.Incident light passing through the first wall 102 is partially absorbedby the absorption layer. The substrate is made from conductive andtransparent materials, such as ITO glass or IZO glass. The absorptionlayer is made from metal, such as aluminum, chromium or silver and soon. The dielectric layer is made from silicon oxide, silicon nitrite ormetal oxide. Metal oxide can be obtained by directly oxidizing a portionof the absorption layer. The second wall 104 is a deformable reflectiveelectrode. It shifts up and down by applying a voltage. The second wall104 is typically made from dielectric materials/conductive transparentmaterials, or metal/conductive transparent materials.

FIG. 2 depicts a cross-sectional view of a display unit in the prior artafter applying a voltage. As shown in FIG. 2, while driven by thevoltage, the wall 104 is deformed and falls down towards the wall 102due to the attraction of static electricity. At this time, the distancebetween wall 102 and 104, that is, the length of the cavity 108 is notexactly zero, but is d, which can be zero. If we use d instead of D informula 1.1, only the visible light with a wavelength satisfying formula1.1, which is λ₂, can generate a constructive interference, and bereflected by the wall 104, and pass through the wall 102. Because wall102 has a high light absorption rate for light with wavelength λ₂, allthe incident light in the visible light spectrum is filtered out and anobserver who follows the direction of the incident light cannot observeany reflected light in the visible light spectrum. The display unit 100is now “closed”.

Refer to FIG. 1 again, which shows that the posts 106 of the displayunit 100 are generally made from negative photoresist materials. Referto FIGS. 3A to 3C, which depict a method for manufacturing a displayunit in the prior art. Referring to FIG. 3A, the first wall 102 and asacrificial layer 110 are formed in order on a transparent substrate109, and then an opening 112 is formed in the wall 102 and thesacrificial layer 110. The opening 112 is suitable for forming poststherein. Next, a negative photoresist layer 111 is spin-coated on thesacrificial layer 110 and fills the opening 112. The objective offorming the negative photoresist layer 111 is to form posts between thefirst wall 102 and the second wall (not shown). A backside exposureprocess is performed on the negative photoresist layer 111 in theopening 112, in the direction indicated by arrow 113 to the transparentsubstrate 109. The sacrificial layer 110 must be made from opaquematerials, typically metal materials, to meet the needs of the backsideexposure process.

Refer to FIG. 3B, which shows that posts 106 remain in the opening 112after removing the unexposed negative photoresist layer. Then, the wall104 is formed on the sacrificial layer 110 and posts 106. Referring toFIG. 3C, the sacrificial layer 110 is removed by a release etchingprocess to form a cavity 114. The length D of the cavity 114 is thethickness of the sacrificial layer 110. Therefore, different thicknessesof the sacrificial layers must be used in different processes of thedifferent display units to control reflection of light with differentwavelengths.

An array comprising the display unit 100 controlled by voltage operationis sufficient for a single color planar display, but not for a colorplanar display. A method in the prior art is to manufacture a pixel thatcomprises three display units with different cavity lengths as shown inFIG. 4, which depicts a cross-sectional view of a matrix color planardisplay in the prior art. Three display units 302, 304 and 306 areformed as an array on a substrate 300, respectively. Display units 302,304 and 306 can reflect an incident light 308 to color lights withdifferent wavelengths, for example, which are red, green and bluelights, due to the different lengths of the cavities of the displayunits 302, 304 and 306. It is not required that different reflectivemirrors be used for the display units arranged in the array. Moreimportant is that good resolution be provided and the brightness of allcolor lights is uniform. However, three display units with differentlengths of cavities need to be manufactured separately.

Please refer to FIGS. 5A to 5D, which depict cross-sectional views of amethod for manufacturing the matrix color planar display in the priorart. In FIG. 5A, the first wall 310 and the first sacrificial layer 312are formed in order on a transparent substrate 300, and then openings314, 316, 318, and 320 are formed in the first wall 310 and thesacrificial layer 312 for defining predetermined positions where displayunits 302, 304, and 306 are formed. The second sacrificial layer 322 isthen conformally formed on the first sacrificial layer 312 and in theopenings 314, 316, 318, and 320.

Please referring to FIG. 5B, after the second sacrificial layer 322 inand between the openings 314 and 316, and in the openings 318 and 320 isremoved by a photolithographic etch process, the third sacrificial layer324 is conformally formed on the first sacrificial layer 312 and thesecond sacrificial layer 322 and in the openings 314, 316, 318 and 320.

Please refer to FIG. 5C, which shows that the third sacrificial layer324 in the openings 318 and 320 remains but the remainder of the thirdsacrificial layer 324 is removed by a photolithographic etch process.Next, a negative photoresist is spin-coated on the first sacrificiallayer 312, the second sacrificial layer 322, and the third sacrificiallayer 324, and in the openings 314, 316, 318 and 320, and fills the allopenings to form a negative photoresist layer 326. The negativephotoresist layer 326 is used for forming posts (not shown) between thefirst wall 310 and the second wall (not shown).

Please refer to FIG. 5D, which shows that a backside exposure process isperformed on the negative photoresist layer 326 in the openings 314,316, 318 and 320 in a direction of the transparent substrate 300. Thesacrificial layer 110 must be made at least from opaque materials,typically metal materials, to meet the needs of the backside exposureprocess. Posts 328 remain in the openings 314, 316, 318 and 320 afterremoving the unexposed negative photoresist layer 326. Subsequently, thesecond wall 330 conformally covers the first sacrificial layer 312, thesecond sacrificial layer 322, the third sacrificial layer 324 and posts328.

Afterward, the first sacrificial layer 312, the second sacrificial layer322, and the third sacrificial layer 324 are removed by a releaseetching process to form the display units 302, 304, and 306 shown inFIG. 4, wherein the lengths d1, d2, and d3 of three display units 302,304, and 306 are the thicknesses of the first sacrificial layer 312, thesecond sacrificial layer 322, and the third sacrificial layer 324,respectively. Therefore, different thicknesses of sacrificial layersmust be used in different processes of the different display units, toachieve the objective for controlling reflection of differentwavelengths of light.

There are at least three photolithographic etch processes required formanufacturing the matrix color planar display in the prior art, todefine the lengths of the cavities of the display units 302, 304, and306. In order to cooperate with the backside exposure for forming posts,metal materials must be used for making the sacrificial layer. The costof the complicated manufacturing process is higher, and the yield cannotbe increased due to the complicated manufacturing process.

Therefore, it is an important subject to provide a simple method ofmanufacturing an optical interference display unit structure, formanufacturing a color optical interference display with high resolution,high brightness, simple process and high yield.

SUMMARY OF THE INVENTION

It is therefore an objective of the present invention to provide amethod for manufacturing an optical interference display unit structure,and the method is suitable for manufacturing a color opticalinterference display with resolution and high brightness.

It is another an objective of the present invention to provide a methodfor manufacturing an optical interference display unit structure, andthe method is suitable for manufacturing a color optical interferencedisplay with a simple and easy manufacturing process and high yield.

It is still another objective of the present invention to provide amethod for manufacturing an optical interference display unit structure,and the method is suitable for manufacturing a color opticalinterference display with posts.

In accordance with the foregoing objectives of the present invention,one preferred embodiment of the invention provides a method formanufacturing an optical interference display unit structure. Theoptical interference display unit structure has a first electrode and asecond electrode. Posts are located between the two electrodes andsupport the electrodes. The feature of the present invention is that thethickness of the second electrode is convertible. Therefore, the stressof the second electrode with different thickness is different. After athermal process, the second electrode may generate displacement bystress action. The distance between two electrodes may alters becausethe different displacement of the second electrode. The method offabricating the optical interference display unit structure is alsodisclosed in the same embodiment.

The first wall and a sacrificial layer are formed in order on atransparent substrate, and then openings are formed in the first walland the sacrificial layer. The openings are suitable for forming poststherein. Next, a photoresist layer is spin-coated on the sacrificiallayer and fills the opening. A photolithographic process patterns thephotoresist layer to define a post. The post could comprise a supportand an arm, the support is formed in one opening and the arm is formedon the top of the support and on the sacrificial layer. The support andthe arm are used for a post.

One or multi conductive layer are formed on the sacrificial layer andposts, and the conductive layer(s) is/are used as the second wall. Thedielectric layer also can be used to alter the thickness or the stressof the second wall. Then, a thermal process, such as a backing processis performed on the structures. The second wall may generate differentdisplacement by stress action because the different stress of the secondwall and the distance between two walls is different. If the post has anarm, the total stress of the arm and the second wall decides thedistance between the two walls. Afterward, the sacrificial layer isremoved by a release etching process to form a cavity, and the length Dof the cavity may not be equal to the thickness of the sacrificial layerdue to the displacement of the second wall.

Additionally, the arms of the post with the ratios of various length tothickness have various amounts of stress, and displacements anddirections generated by arms are various during baking. Therefore, thearms with the ratios of various lengths to thickness and the thicknessof the second wall may be used for controlling the length of the cavity,instead of the various thickness of the sacrificial layers used in thevarious processes of the display units to control various wavelengths oflight reflected in the prior art. There are many advantages in the aboveway. First of all, the cost drops drastically. The thickness of thecavity in the prior art is the thickness of the sacrificial layer, andthe sacrificial layer needs to be removed at the end of the process.However, using an upward displacement of the second wall in the presentinvention increases the length of the cavity, so that the length of thecavity is greater than the thickness of the sacrificial layer, even ifthe thickness of the sacrificial layer is substantially decreased whileforming the same length of cavities. Therefore, the material used formanufacturing the sacrificial layer is substantially reduced. Thesecond, the process time is shortened. The release etching process ofthe metal sacrificial layer in the prior art consumes lots of time,because the sacrificial layer is removed by an etching gas that mustpermeate the spaces between the posts. The present invention utilizes amask for a front exposure, so the sacrificial layer can be transparentmaterials such as dielectric materials, instead of opaque materials suchas metal and the like as in the prior art. Besides, the thickness usedby the sacrificial layer can be substantially reduced, so the timerequired for the release etching process can be also drasticallydecreased. Third, the color optical interference display formed by usingposts can substantially reduce complexity of the process. The differencein the ratios of thickness of the second wall is used for changing thestress of the second wall. After baking, various optical interferencedisplay units have various lengths of the cavities due to thedisplacement of the second wall, such that reflected light is changedwith various wavelengths, such as red, green, and blue lights, so as toobtain various color lights.

In accordance with another an objective of the present invention, onepreferred embodiment of the invention provides a method formanufacturing a matrix color planar display structure. Each matrix colorplanar display unit has three optical interference display units. Thefirst wall and a sacrificial layer are formed in order on a transparentsubstrate, and then an opening is formed in the first wall and thesacrificial layer. The opening is suitable for forming posts therein.Next, a photoresist layer is spin-coated on the sacrificial layer andfills the opening. A photolithographic process patterns the photoresistlayer to define a support with an arm. The support and the arm are usedfor a post, and to define the length of the arm. Afterward, a firstelectrode layer is formed on the three optical interference display unitand a second electrode layer is formed on the first electrode layerwhich is on the second and the third optical interference display units.Thereafter, a third electrode layer is formed on the second electrodelayer which is on the third optical interference display unit. The firstelectrode layer is the second wall of the first optical interferencedisplay unit, the first electrode layer and the second electrode layerare the second wall of the second optical interference display unit, andthe first electrode layer, the second electrode layer and the thirdelectrode layer are the second wall of the third optical interferencedisplay unit. Therefore, the thickness of the second wall of the threeoptical interference display unit is different and the stress of thesecond wall on the three optical interference display unit is different,too. In this embodiment, due to the exposure of the photoresist layerwith the help of a mask, the sacrificial layer no longer must be anopaque material such as metal and the like; common dielectric materialsare also used for making the sacrificial layer.

The second wall is formed on the sacrificial layer and posts, and thenbaking is performed on the posts. The second wall may generatedisplacement by stress action. The displacements of the second walls ofthe different optical interference display unit are different becausethe thickness of the second wall of the different optical interferencedisplay unit is different. Afterward, the sacrificial layer are removedby a release etching process to form a cavity, and the length D of thecavity may not be equal to the thickness of the sacrificial layer due tothe displacement of the arm.

The first wall is the first electrode, and the second wall is the secondelectrode. The thickness of the second wall of the different opticalinterference display unit is different, however, the stress of thesecond wall of the different optical interference display unit is alsodifferent. Therefore, the displacement of the second electrodes isdifferent after a baking process. The distance between the twoelectrodes, i.e. the length of the cavity, of the different opticalinterference display unit is different. Therefore, after baking, eachoptical interference display unit has various cavity lengths, such thatreflected light is changed with different wavelengths, such as red,green, and blue light. These in turn provide various color lights for amatrix color planar display structure.

In accordance with the color planar display consisting of an array ofoptical interference display units disclosed by the present invention,the advantages of a matrix color planar display according to the priorart are retained, including high resolution and high brightness, as wellas the advantages of a multi-layered color planar display with a simpleprocess and high yield in the prior art. It is understood that thepresent invention discloses an optical interference display unit whichnot only keeps all advantages of the prior optical interference colorplanar display such as high resolution, high brightness, simple processand high yield during forming arrays, but also increases the windowduring processing and raises the yield of the optical interference colorplanar display.

It is to be understood that both the foregoing general description andthe following detailed description are examples, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWING

These and other features, aspects, and advantages of the presentinvention will be more fully understood by reading the followingdetailed description of the preferred embodiment, with reference made tothe accompanying drawings as follows:

FIG. 1 depicts a cross-sectional view of a display unit in the priorart;

FIG. 2 depicts a cross-sectional view of a display unit in the prior artafter applying a voltage;

FIGS. 3A to 3C depict a method for manufacturing a display unit in theprior art;

FIG. 4 depicts a cross-sectional view of a matrix color planar displayin the prior art;

FIGS. 5A to 5D depict cross-sectional views of a method of manufacturinga matrix color planar display in the prior art; and

FIGS. 6A to 6E depict a method for manufacturing an optical interferencedisplay unit according to one preferred embodiment of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In order to provide more information of the optical interference displayunit structure, the first embodiment is provided herein to explain theoptical interference display unit structure in this invention. Inaddition, the second embodiment is provided to give further descriptionof the optical interference color planar display formed with an array ofthe optical interference display unit.

Embodiment 1

FIGS. 6A to 6E depict a method for manufacturing an optical interferencedisplay unit according to a preferred embodiment of the invention.Please referring to FIG. 6A first, a first electrode 602 and asacrificial layer 604 are formed in order on a transparent substrate601. The sacrificial layer 604 is made of transparent materials such asdielectric materials, or opaque materials such as metal materials.Opening 606, 608, 610 and 612 are formed in the first electrode 602 andthe sacrificial layer 604 by a photolithographic etching process. Theopenings 606, 608, 610 and 612 are suitable for forming a post therein.

Next, a material layer 614 is formed on the sacrificial layer 604 andfills the openings 606, 608, 610 and 612. Openings 606 and 608, openings608 and 610, and openings 610 and 612 are used to define the location ofthe optical interference display units 630, 632 and 634. The materiallayer 614 is suitable for forming posts, and the material layer 614generally uses photosensitive materials such as photoresists, ornon-photosensitive polymer materials such as polyester, polyamide or thelike. If non-photosensitive materials are used for forming the materiallayer 614, a photolithographic etch process is required to define postsin the material layer 614. In this embodiment, the photosensitivematerials are used for forming the material layer 614, so merely aphotolithographic etching process is required for patterning thematerial layer 614.

Please referring to FIG. 6B, the posts 616, 618, 620 and 622 are definedby patterning the material layer 614 during a photolithographic process.The posts 616, 618, 620 and 622 have supports 6161, 6181, 6201 and 6221disposed in the openings 606, 608, 610 and 612, and the posts 616, 618,620 and 622 have arms 6122, 6182, 6183, 6202, 6203 and 6222. The lengthof arms 6122, 6182, 6183, 6202, 6203 and 6222 is same. Therefore, thearea of the optical interference display units 630, 632 and 634 forreflecting incident light is similar.

Reference is next made to FIG. 6C. A first electrode layer 624 is formedon the sacrificial layer 604 and the arms 6122, 6182, 6183, 6202, 6203and 6222. Next, a second electrode layer 626 is formed on the firstelectrode layer 624, which is located on the optical interferencedisplay units 632 and 634. Then, a third electrode layer 628 is formedon the second electrode layer 626 which is located on the opticalinterference display unit 634. Reference is further made to FIG. 6C. Thefirst electrode layer 624 on the optical interference display unit 630is used as the second electrode 636 of the optical interference displayunit 630, the first electrode layer 624 and the second electrode layer626 on the optical interference display unit 632 are used as the secondelectrode 638 of the optical interference display unit 632, and thefirst electrode layer 624, the second electrode layer 626 and the thirdelectrode layer 628 on the optical interference display unit 634 areused as the second electrode 640 of the optical interference displayunit 634.

There are several fabricating processes to form the second electrodedisclosed above. When the same material for forming the electrode layersis used, a deposition process is performed to form a enough thickelectrode layer on the sacrificial layer and the posts and at least onephotolithographic process and at least one time control etching processare adapted to form the second electrode with different thickness on thedifferent optical interference display unit. When more than one materialfor forming the electrode layers are used, deposition processes areperformed to form a enough thick electrode layers on the sacrificiallayer and the posts and at least one photolithographic process and atleast one selective etching process are adapted to form the secondelectrode with different thickness on the different optical interferencedisplay unit. The materials for forming the electrode layers could beconductive transparent material, metal, conductive opaque material,conductive hemi-transparent material and dielectric material.

Referring is made to FIG. 6D, a thermal process is performed, such asbaking. The second electrode 636, 638 and 640 of the opticalinterference display unit 630, 632 and 634 may generate displacement bya stress action. The arms 6162, 6182, 6183, 6202, 6203, and 6222 of theposts 616, 618, 620, and 622 may also generate displacement as the pivotof the supports 6161, 6181, 6201, and 6221 caused by stress action.There is less displacement at the ends of the arms 6162, 6182, 6183,6202, 6203, and 6222 adjacent to the supports 6161, 6181, 6201, and6221, but more displacement at the other ends of the arms 6162, 6182,6183, 6202, 6203, and 6222. The arms 6162, 6182, 6183, 6202, 6203, and6222 meet the second electrode 636, 638 and 640, which have differentthickness and stress, therefore, there are various changes in thepositions of the second electrode 630 caused by the arms 6162 and 6182,the arms 6183 and 6202, and the arms 6203 and 6222.

Thereafter, reference is made to FIG. 6E. The sacrificial layer 604 isremoved by a release etching process to form the cavities 6301, 6321,and 6341 of the optical interference display units 630, 632, and 634.The cavities 6301, 6321, and 6341 have various lengths d₁, d₂, and d₃,respectively. When the optical interference display units 630, 632, and634 are “open”, as shown as the formula 1.1, the design of lengths d₁,d₂, and d₃ of the cavities 6301, 6321, and 6341 can generate thereflected light with different wavelengths, such as red (R), green (G),or blue (B) light.

The lengths d₁, d₂, and d₃ of the cavities 6301, 6321, and 6341 are notdecided by the thickness of the sacrificial layer, but by the thicknessof the second electrode 636, 638 and 640, respectively. Therefore, thecomplicated photolithographic process of the prior art to define variouslengths of the cavities forming various thicknesses of the sacrificiallayers is unnecessary.

The arms disclosed in the preferred embodiment are not necessary. Evenin the case without the arms, the second electrode with differentthickness may generate different displacement by a stress action after athermal process.

In accordance with the color planar display consisting of the array ofoptical interference display units disclosed by this embodiment, theadvantages of a matrix color planar display in the prior art areretained, including high resolution and high brightness, as well as theadvantages of the prior art multi-layered color planar display such assimple process and high yield. Compared with the matrix color planardisplay in the prior art, the embodiment discloses an opticalinterference display unit that does not require the complicatedphotolithographic process in the prior art to define various lengths ofthe cavities by forming various thicknesses of the sacrificial layers.The optical interference display unit thus has a simple process and highyield. Compared with the matrix color planar display in the prior art,the embodiment discloses an array of optical interference display units,in which all the optical interference display units that can generatereflected color light are located in the same plane. In other words, theincident light can reflect various color lights without passing throughthe multi-layered optical interference display unit; thus, the opticalinterference display unit has high resolution and high brightness.Furthermore, in the multi-layered optical interference display in theprior art, in order to make an incident light to pass through a formerdisplay unit and reach a latter display unit efficiently, and the resultof light interference in the latter display unit (reflected light ofgreen or blue light wavelength) to pass through a former display unitefficiently, the compositions and thicknesses of the first electrode andthe second electrode of three types of display units are different. Themanufacturing process is actually more complicated than expected. Theprocess for the array of the optical interference display unitsdisclosed by this invention is less difficult than the process in theprior art.

Although the present invention has been described in considerable detailwith reference certain preferred embodiments thereof, other embodimentsare possible. Therefore, their spirit and scope of the appended claimsshould no be limited to the description of the preferred embodimentscontainer herein. In view of the foregoing, it is intended that thepresent invention cover modifications and variations of this inventionprovided they fall within the scope of the following claims and theirequivalents.

1-8. (canceled)
 9. A method for manufacturing a matrix color opticalinterference display unit disposed on a substrate, the methodcomprising: forming a first electrode on the substrate; forming asacrificial layer on the first electrode; forming at least four openingsin the sacrificial layer and the first electrode to define positions ofa first optical interference display unit, a second optical interferencedisplay unit, and a third optical interference display unit; forming apost in each of the openings; forming at least one first electrode layeron the sacrificial layer and the posts; forming at least one secondelectrode layer on the first electrode layer located on the secondoptical interference display unit and the third optical interferencedisplay unit; forming at least one third electrode layer on the secondelectrode layer located on the third optical interference display unit;performing a thermal process; and removing the sacrificial layer. 10.The method for manufacturing a matrix color optical interference displayunit of claim 9, wherein the first electrode layer forms the secondelectrode of the first optical interference display unit.
 11. The methodfor manufacturing a matrix color optical interference display unit ofclaim 9, wherein the first electrode layer and the second electrodelayer form the second electrode of the second optical interferencedisplay unit.
 12. The method for manufacturing a matrix color opticalinterference display unit of claim 9, wherein the first electrode layer,the second electrode layer and the third electrode layer form the secondelectrode of the second optical interference display unit.
 13. Themethod for manufacturing a matrix color optical interference displayunit of claim 10, wherein a material for forming the posts is selectedfrom a group consisting of photosensitive materials, non-photosensitivematerials and a combination thereof.
 14. The method for manufacturing amatrix color optical interference display unit of claim 13, wherein thephotosensitive materials are a photoresist.
 15. The method formanufacturing a matrix color optical interference display unit of claim9, wherein the post comprises a support and at least one arm.
 16. Themethod for manufacturing a matrix color optical interference displayunit of claim 15, wherein the step of forming the post furthercomprises: forming a first photosensitive material layer to fill theopenings and cover the sacrificial layer; and patterning the firstphotosensitive material layer to form the support in each of theopenings and the arm on the support.
 17. The method for manufacturing amatrix color optical interference display unit of claim 13, wherein thestep of patterning the first photosensitive material layer includes aphotolithographic process.
 18. The method for manufacturing a matrixcolor optical interference display unit of claim 15, wherein the stepfor forming the support and the arm further comprises: forming a firstnon-photosensitive material layer to fill the openings and cover thesacrificial layer; and patterning the first non-photosensitive materiallayer to form the support in each of the openings and the arm on thesupport by a photolithographic etch process.
 19. The method formanufacturing a matrix color optical interference display unit of claim9, wherein the thermal process is baking.
 20. The method formanufacturing a matrix color optical interference display unit of claim9, wherein the thermal process makes the second electrode to generatedisplacement due to stress.
 21. The method for manufacturing a matrixcolor optical interference display unit of claim 9, wherein the secondelectrode is a deformable electrode.
 22. The method for manufacturing amatrix color optical interference display unit of claim 9, wherein thesecond electrode is a movable electrode.
 23. The method formanufacturing a matrix color optical interference display unit of claim9, wherein a material for forming the second electrode is conductivetransparent material, metal, conductive opaque material, conductivehemi-transparent material or dielectric material.